Knife-sharpener



0. K. BRADFORD. KNIFE SHARPBNBR (No Model.)

No. 450,215. Patented Abr. 14, 1891.

UNITED STATES PATENT OFFICE.

CHARLES K. BRADFORD,VOF LYNNFIELD, ASSIGNOR TO BRADFORD 00., OF BOSTON, MASSACHUSETTS KNIFE-SHARPENER.

SPECIFICATION forming part of Letters Patent No. 450,215, dated April 14, 1891.

Application filed June 23, 1890. Serial No. 356.403. (No model.)

To all whom it may concern:

Be it known that I, OHA LEs K. BRADFORD, of Lynnfield, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Knife-Sharpen ers, of which the following is a specification.

This invention relates to knife-Sharpeners in which two metal blades are arranged to present two edges, which together form a V- shaped slot or recess between which the knife to be sharpened is drawn, the edge of the knife being sharpened by contact with the intersecting edges at the angle of the V-shaped recess.

The invention consists in the detailed construction and combination of parts, as hereinafter disclosed.

Of the accompanying drawings, forming a part of this specification, Figure 1 represents a side elevation of a knife-sharpener embodying my improvements. Fig. 2 represents an edge view of the same. Fig. 3 represents an enlarged section on line 3 3, Fig. 1. Fig. 4 represents a side elevation, showing a different adjustment of the blades. Fig. 5 represents an elevation of the side opposite to that shown in Figs. 1 and at, showing the scissorsguide. Fig. 6 represents a side view of the scissors-guide detached.

The same letters of reference indicate the same parts in all the figures.

In carrying out my invention I provide two blades 0. a, each of which is a flat piece of steelhavingaseries of arms radiating from its center. The blades are placed one against the other and are connected at their centers by a screw 17, which enters a holder d, hereinafter described, and when tightened clamps the outer blade against the inner, so that the blades cannot slip or turn. Each arm of the blade at has two beveled edges 4: at, and each arm of the blade at has two beveled edges 5 5'. Said arms are so formed that there is a V-shaped recess between each arm of one blade and the adjacent arm of the other blade, the said beveled edges constituting the sides of said recesses. The beveled form of said edges gives each an acute angle, as shown in Fig. 3, so that when a knife-blade is drawn through either recess in the direction indicated by the arrow in Fig. 3 its sides at and near its edge will be planed off so as to form a sharp cutting-edge.

When the beveled edges that constitute the highest V-shaped recess, or the one above the upper end of the holder d, become dull, the blades may be loosened and partly rotated until another recess reaches said position, thus bringing a fresh pair of planing-edges into convenient operative position, and this 6ooperation can be repeated until one set of edges on each plate have become dull. After this one plate can be moved relatively to the other to cause the other edges of the radiating arms to form the V-shaped recesses, as shown in Fig. 4, the extent of movement of one plate on the other to efiect this change being determined by a stud e on one plate, said stud projecting into the space between two arms of the other plate and bearing against one edge of said space, as shown in Fig. 1, when the plates are adjusted to bring the edges 4 of the blade a into operative relation with the edges 5 of the blade at and against the opposite edge of said space, as shown in Fig. 4, when the plates are adjusted to bring the edges 4 of the blade a into operati've relation with the edges 5 of the blade 0,.

g represents a guide, which is attached to the device as an aid in sharpening shears and scissors. Said guide is. a sheet-metal plate which is inserted between the holder (1 and the inner blade, and has a central hole g to .3 receive the screw 1). The lower portion of the guide 9 has a recess 9 the edges of which 8 are bent outwardly to form tongues g g arranged to bear on opposite sides of the holder at to prevent the rotation of the said guide g. The guide is provided at its ,upper portion with a projection g having an inclosed edge 0 G,which stands at such an angle to one of the planing-edges that when the inner side of a shear or scissors blade 8 bears against said edge 6 the cutting-edge of said blade will bear properly on the said planing-edge, as shown 5 in Fig. 5, so that the blade will be properly planed or dressed when it is moved lengthwise while in contact with said planing-edge. The plate constituting the guide g is notched or recessed at g so that it will not interfere Ice with or toucha knifeblade that is being drawn through the upper V-shaped recess.

The holder at is provided with arms d d arranged to receive between them one edge of atable or shelf, the lower arm 61 having a thumbscrew d which is adapted to bear against the bottom of said table or shelf, and thus secures the sharpening device thereto.

It will be seen that the device as a whole comprising the adjustable multiple-edged blades and the clamp supporting the same, constitutes a simple, convenient, and effective sharpening device, which is capable of being used a long time without losing its effectiveness.

I claim- In a knife-sharpener, the combination, with the blades having the series of peripheral bevel-edged arms, and their holder having the blade adjusting and holding screw, of the scissors or shear blade guide having an inclined edge, the base of which is adapted to stand tangentially to the beveled edges of the arms of one of said blades as they are successively brought into use, said guide also having a 

